[Code of Federal Regulations]
[Title 40, Volume 19]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR146.4]

[Page 699-700]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 146--UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 146.4  Criteria for exempted aquifers.

    An aquifer or a portion thereof which meets the criteria for an 
``underground source of drinking water'' in Sec. 146.3 may be determined 
under 40 CFR 144.8 to be an ``exempted aquifer'' if it meets the 
following criteria:
    (a) It does not currently serve as a source of drinking water; and
    (b) It cannot now and will not in the future serve as a source of 
drinking water because:
    (1) It is mineral, hydrocarbon or geothermal energy producing, or 
can be demonstrated by a permit applicant as part of a permit 
application for a Class II or III operation to contain minerals or 
hydrocarbons that considering their quantity and location are expected 
to be commercially producible.
    (2) It is situated at a depth or location which makes recovery of 
water for drinking water purposes economically or technologically 
impractical;
    (3) It is so contaminated that it would be economically or 
technologically impractical to render that water fit for human 
consumption; or
    (4) It is located over a Class III well mining area subject to 
subsidence or catastrophic collapse; or
    (c) The total dissolved solids content of the ground water is more 
than 3,000 and less than 10,000 mg/l and it is not

[[Page 700]]

reasonably expected to supply a public water system.

(Clean Water Act, Safe Drinking Water Act, Clean Air Act, Resource 
Conservation and Recovery Act: 42 U.S.C. 6905, 6912, 6925, 6927, 6974)

[45 FR 42500, June 24, 1980, as amended at 47 FR 4998, Feb. 3, 1982; 48 
FR 14293, Apr. 1, 1983]